High resolution X-ray diffraction of one- and two-dimensional periodic surface gratings

(Received 19 November 1993, revised 6 April 1994, accepted 30 May 1994)

Abstract
From one- and two-dimensional periodic surface gratings in Si and InP very clear satellite peaks are obtained in a rocking curve provided the appropriate diffraction geometry is chosen. For (001) oriented Si, InP or GaAs substrates with corrugations in the [110] direction, measured with CuK , the optimal geometry is best approximated by the 113 reflection using the high angle of incidence. Due to beam compression, caused by the asymmetry of the reflection, this reflection is also suited to obtain two-dimensional reciprocal space maps from one- and two dimensional surface gratings. A narrow slit can be used to obtain adequate detector resolution. The maps reveal in detail the shape of the grating. They are compared with simple model calculations based on Fourier transformation of the shape of the grating-crystal assembly.